Filament wont go into extruder box

Bambu Lab P Series Troubleshooting
1

I have a P1S with and AMS. I have been having problems since I had a clog.

Alright, been having a fit with my printer. I was having problems with the filament reaching the extruder. I changed out the filament roll and now it reaches the extruder every time.

The problem is, the filament wont go into the extruder. The filament seems to “hit a wall.” It just seems to get stuck hitting something. I took apart the TH and opened the extuder gear box. Nothing was stuck in it. I was able to push filament through it without an issue. Made sure the tube say right into the extrudwe. I also changed out the nozzle.

Any idea what could he happening? Its like the filament wont hit the gears, or the gears may not be moving inside the extruder. Good it be the AMS not pushing the filament in hard enough?

I checked the tubes and everything else i could think of. I think it all comes to filament not getting in the extruder box.

Please, help me. Thanks.

2

If you run the extruder manually from the front panel, do you see the gear turn?

3

I will have to try that now. I will get back to you. Thanks.

4
  • Residual Clog in the Heatbreak: Even if the nozzle was changed, a piece of broken or expanded filament might still be stuck higher up in the heatbreak (the metal tube between the extruder gears and the hotend).
    • Solution: Perform a “cold pull” procedure. Heat the hotend to printing temperature, push a little filament in, then cool it to a lower temperature (around 90-100°C for PLA) and pull it out sharply to extract any debris. If this fails, the toolhead may need to be disassembled further to physically clear the blockage.
  • Filament Expansion/Heat Creep: The existing filament in the heatbreak might have softened and expanded, making it impossible for the new filament or the extruder gears to push it down.
    • Solution: The cold pull method is effective for this, as it removes the expanded section. Ensuring proper cooling fan function can prevent future heat creep issues.
  • Damaged Extruder Sensor: The internal sensor in the extruder might not be
5

will the filament load WITHOUT the AMS? I had a similar problem that turned out to be a small piece of filament stuck in the INTERNAL hub of the AMS.

6

I have done a cold pull, but only once through the nozzle. When you say, “heat break”, is that in the extruder or the nozzle?

I have a new sensor coming from Bambu. Just have to wait. I am willing to try anything at this moment. Thanks.

7

Still wont. The AMS is pushing the filament okay. It just stops at the top of the extruder.

8

Also, when i say nozzle, i mean the whole piece. The nozzle, sock, fan, everything. I put a whole new piece on like I just bought it.

9

The heat break is the part that keeps the filament from melting too fast in the extrude, which helps prevent clogging

10

It can help a lot to troubleshoot not from the AMS but from the rear spool.
There are a number of possible stops within a short space which are easier to nail down by trying to extrude manually using the rear spool and the control panel:

  • PTFE exit into Extruder: Worn tube? Cut with a very slight angle? Just recut or replace the PTFE and make sure it is fully pushed in.
  • PTFE coupler at the top of the filament sensor? These can wear out but are replaceable (pack of 3 PTFE couplers contains 6 that you can use). A “spare” can be taken from the rear of that same PTFE.
  • Extruder contamination (but you already checked that
  • Stuck/worn filament cutter (replace and check smooth operation)
  • Blocked nozzle (but you replaced the hotend already, so unlikely)
  • Misaligned Hotend (reinstall)

What could be helpful is a pic of your open print head with a line drawn at the location where manual feeding leads to a block. But I daresay you are likely to resolve the problem yourself with that pic.

:crossed_fingers: & :four_leaf_clover:

11

I have had this exact same problem. I have done every single troubleshoot and replaced the filament sensor and still no luck. Did you have success with anything you have tried yet? I debated on replacing the entire extruder to see if that would fix the issue.

12

I am having a similar issue, but mine is that the extruder is smashing/crushing the filament, does not letting it go through the hotend. Any of you in a similar situation?